The method under discussion is used in connection with the motor-operated adjustment of a hatch leaf of a motor vehicle. The term “hatch leaf” is to be understood in a broad sense in respect of the said method. Hatch leaves include tailgates, boot lids, engine bonnets, doors, in particular side doors, load-space floors or the like of a motor vehicle.
Hatch arrangements of motor vehicles, which hatch arrangements are equipped with a hatch drive for the motor-operated adjustment of a hatch leaf, are increasingly being used to improve user convenience. Hatch drives of this kind have already become widely accepted for use in single-leaf hatch arrangements (WO 2010/046008 A1). In this case, the hatch drive is generally equipped with a drive controller for implementing a respectively predefined setpoint hatch adjustment operation. The setpoint hatch adjustment operation is prespecified by operation by a user pressing, for example, the open button or close button of a radio key.
The hatch leaf can be adjusted between an open position and a closed position by means of the hatch drive. During a closing process in the closing direction, a motor vehicle lock which is arranged on the hatch leaf engages with a lock striker, which is fixed to the vehicle body, and as a result enters a latching state in which it retains the lock striker for the time being. A lock latch engages in a latching manner with a pawl of the motor vehicle lock in the latching state.
One requirement of the known hatch arrangement from a control aspect is that of preventing the motor vehicle lock and the lock striker engaging in a retaining manner in a way which is not desired. This situation can occur, for example, as a result of the user initiating a reversing process starting from the closing process shortly before the closed position is reached. In the present context, a “reversing process” is to be understood to mean the process with which the movement direction is briefly reversed after the reversing process is initiated.
The initiation of the reversing process is not always followed by an ideally immediate movement reversal since the mass inertia of the hatch leaf and other influences cause the hatch leaf to perform a certain coasting movement in the closing direction. An appreciable coasting movement is to be expected in the case of the known arrangements even when the supply of power to the hatch drive is reversed immediately after the reversing process is initiated.
The fact that a coasting movement of the above kind always occurs in the event of a reversing operation can be problematical in the event of a reversing operation starting from a closing process shortly before the closed position. In this case, the coasting movement can lead, specifically, to the lock striker engaging in a retaining manner with the motor vehicle lock such that the supply of power to the hatch drive in the opening direction counteracts the retaining force of the motor vehicle lock. Even though the user has initiated a reversing process, the hatch leaf remains “stuck” to the lock striker, this being accompanied by a reduction in the operational reliability of the hatch arrangement overall.